It has previously been proposed to provide apparatus which enables the doors or other opening parts of something that is capable of being broken into by unauthorised persons, and in particular a motor vehicle, to be unlocked by remote control, and therefore without any contact, either electrical or mechanical, with the doors or other opening parts. In particular, keyless access techniques have been developed which enable access to be gained to a vehicle without the need to find a mechanical key, or the equivalent of a key, in order to gain access.
Such a system is very attractive from the comfort or convenience point of view and also because it offers various possibilities for obtaining access using modern information technology.
In the application of this concept to the locking and unlocking of opening parts, such as doors, for example those of a motor vehicle, or the locking and unlocking of an anti-theft security system for a vehicle, such as that which involves locking the steering column or the output shaft of the gearbox of a vehicle, mechanical systems have been proposed in these contexts which employ electrical actuating devices, for example a rotary electric motor or an electromagnet.
When the system for obtaining access recognises that a right of access exists, and that an unauthorised demand for access also exists, a control member produces a command for actuation of the system which excites the electrical actuating device. The anti-theft system and/or the lock changes state by passing from the locked condition to the unlocked condition. When the user leaves the vehicle, and/or when it is desired to activate the anti-theft system, a similar sequence takes place in reverse.
In one known design, which is described and shown in the specification of French patent application No. 93 11671 of 30 Sep. 1993, it was proposed to provide a method of control for an anti-theft system for a motor vehicle, in particular with a remote control access system, which, in particular, employs a switch for controlling starting of the vehicle, and the supply of electrical power to various electrical circuits of the vehicle, in particular the power supply circuits for the accessories and the ignition circuit for the engine of the vehicle.
In that method, during a phase of deactivation of the anti-theft system, contact is made with the vehicle by means of, for example, a telecontrol unit. An anti-theft security switch is then operated, which reproduces the manipulation of the conventional mechanical keys, and a predetermined position of the security switch is detected so as to set up an interrogation procedure in order to identify the demand to unlock the anti-theft system. In response to this, a command or order for actuation of successive positions of the security switch, and finally a command to unlock the anti-theft system, are produced.
In an activating phase of the anti-theft system, the step in which the anti-theft system is activated by operation of the security switch is detected. This operation of the switch reproduces the conventional manipulations of mechanical keys. Once this step is completed, the system is activated, and the successive positions of the security switch are deactivated.
In order to realise such a procedure in practice, it is necessary to provide an electrical anti-theft security system of the type comprising:
an anti-theft security switch for controlling the power supply to various electrical circuits of the vehicle; PA1 a motorised security device comprising a motorised blocking member such as a steering column lock, which includes an electric motor for moving the blocking member between a locked position and an unlocked position; PA1 and a central anti-theft unit which is connected to the elements mentioned above for the purpose of implementing a procedure in which the anti-theft system is armed or disarmed. PA1 a key interruptor for detecting simulation of the introduction of a key into the anti-theft switch; PA1 and a multiple position control interruptor for controlling, in sequence, the power supply for the said electrical circuits of the vehicle, this control interruptor comprising a movable control contact which is connected to one polarity of a power supply source, and a set of fixed contacts with which the movable contact makes successive contact during operation of the security switch with a view to enabling the vehicle to be started, the control interruptor being unable to be actuated except in the presence of a key. PA1 an anti-theft security switch for controlling the power supply to various electrical circuits of the vehicle; PA1 a motorised security device comprising a motorised blocking member such as a steering column lock, which includes an electric motor for moving the blocking member between a locked position and an unlocked position; PA1 and a central anti-theft unit which is connected to the elements mentioned above for the purpose of implementing a procedure in which the anti-theft system is armed or disarmed, the system being also of the type in which the anti-theft security switch comprises: PA1 an interruptor for detecting that the anti-theft system is in its locked condition, comprising a movable contact which is connected to one polarity of the power supply source, and which is arranged to cooperate with a fixed contact that is connected, when the system is in its locked condition, to the said input of the central anti-theft unit for detection of the locked condition of the system; and PA1 an interruptor for detection that the anti-theft system is in its unlocked condition, comprising a movable contact which is connected to one polarity of the power supply source, and which is arranged to cooperate with a fixed contact that is connected, when the system is in its unlocked condition, to the said input of the central anti-theft unit for detection of the unlocked condition of the system.
This system is also of the type in which the anti-theft security switch comprises:
An electrical anti-theft security system has to give the user the same degree of security as an anti-theft system having conventional key-operated mechanical control; and in particular it must be able to prevent any starting of the vehicle when the above mentioned blocking member of the motorised security device is not in its unlocked position.
Preferably it must also avoid any possibility of the system being activated towards its locked position when the vehicle is moving.